A natural material, wood, generally requires modification of its characteristics such as putrefaction, dimensional instability and inflammability depending upon its utility. For example, antibacterial, antifungal and insecticidal treatments of wood by using a preservation agent is generally achieved by providing the wood with water repellency by adding paraffin, a surface active agent, etc. to the preservation agent. Also, gas oil, light oil, a high boiling point kerosin fraction and the like are used as preservative solvents to improve the penetrating property. Since these solvents have high boiling points, however, the treated wood becomes hard to dry. Components in these treating compositions must necessarily be safe to human as well as under working conditions.
Hitherto, impregnation of wood with inorganic substances has been considered, but the most important problem in such an impregnation is a low impregnated amount in wood. It is technically difficult to introduce the inorganic substances into an inner vessel portion of the center of wood by impregnation. When the wood is forcedly impregnated, the inorganic substances tend to be leaked out and are thus difficult to be fixed in the wood. Further, such a forced impregnation causes discoloration of wood, thereby reducing its commercial value, and also may cause decoloration of coating materials applied on the surface of the impregnated wood. When sodium silicate is used for impregnation, parenchyma tend to be deteriorated due to a strong alkalinity of sodium silicate. In addition, the wood treating agents must be selected so as not to discharge strongly toxic gases and/or heavy metals when the treated woods are disposed as scrap wood after passing its durable years.
Woods are basically limited natural resource and become usable materials after growth for a long period of term, and hence reinforcement and improvement of the functions of the woods are problems which have conventionally been desired to be solved. Accordingly, a wood modifier composition which is practically useful for providing the wood with functions such as non-putrefaction, fire-resistance, dimension stability, non-attack by harmful insects is strongly desired while retaining decomposability in the ground.